1. Field of the Invention
The present invention relates to apparel. The invention concerns, more particularly, an article of apparel having a stratified material that includes incisions to define areas of stretch in the apparel.
2. Description of Background Art
Articles of apparel are generally formed from planar elements of material, such as textiles, that are joined together to form a structure that receives a portion of the human body. In general, the human body exhibits a shape that is not easily reproduced by merely planar elements of material. That is, articles of apparel are designed from planar elements of material to accommodate a shape that is non-planar and may vary significantly in proportions from one individual to another individual. Although differences between individuals may be accommodated through articles of apparel with various sizes or stretch properties, individuals with a common size may exhibit significantly different proportions.
An example of an article of apparel that accommodates portions of the human body with varying sizes and proportions is footwear. Conventional articles of athletic footwear generally include two primary elements, an upper and a sole structure. The upper is secured to the sole structure and forms a void on the interior of the footwear for comfortably and securely receiving a foot. The sole structure is positioned between the foot and the ground to attenuate ground reaction forces as the footwear impacts the ground.
The upper generally extends over the instep and toe areas of the foot, along the medial and lateral sides of the foot, and around the heel area of the foot. Access to the void on the interior of the footwear is generally provided by an ankle opening. A lacing system is often incorporated into the upper to selectively increase the size of the ankle opening and permit the wearer to modify certain dimensions of the upper, particularly girth, to accommodate feet with varying dimensions. In addition, the upper may include a tongue that extends under the lacing system to enhance the comfort of the footwear, and the upper may include a heel counter to limit movement of the heel.
Various materials may be utilized in manufacturing the upper. The upper of athletic footwear, for example, may be formed from multiple material layers that include an exterior layer, a middle layer, and an interior layer. The materials forming the exterior layer of the conventional upper may be selected based upon the properties of wear-resistance, flexibility, and air-permeability, for example. With regard to the exterior layer, the toe area and the heel area may be formed of leather, synthetic leather, or a rubber material to impart a relatively high degree of wear-resistance. Leather, synthetic leather, and rubber materials may not exhibit the desired degree of flexibility and air-permeability. Accordingly, various other areas of the exterior layer of the upper may be formed from a synthetic textile. The exterior layer of the upper may be formed, therefore, from numerous material elements that each impart different properties to the upper.
The middle layer of the conventional upper may be formed from a lightweight polymer foam material that provides cushioning and protects the foot from objects that may contact the upper. Similarly, the interior layer of the conventional upper may be formed of a moisture-wicking textile that removes perspiration from the area immediately surrounding the foot. In some articles of athletic footwear, the various layers may be joined with an adhesive, and stitching may be utilized to join elements within a single layer or to reinforce specific areas of the upper.
Based upon the above discussion, the conventional upper is formed from multiple layers, and each layer may be formed from multiple material elements. In manufacturing the upper, the specific materials utilized for each layer and element are selected and then cut to a predetermined shape. Considerable effort is then expended in joining the various elements together, particularly the various material elements forming the exterior layer of the upper.